1. Field of the Invention
The present invention relates to an augmented reality provision system including an imaging unit that images a real space, and a display unit that superimposes an object image indicating a virtual object on a captured image obtained through imaging in the imaging unit to display the object image, a method, and a non-transitory computer readable medium.
2. Description of the Related Art
An augmented reality provision system capable of performing AR (Augmented Reality) display in which a virtual object is superimposed on an image of a real space and displayed has been recently developed. For example, various image processing methods in which appropriate color adjustment is performed on an object image so as to increase senses of reality and presence of a virtual object have been proposed.
A method of calculating a transformation parameter from color of a pattern drawn in a marker expressing AR display and correcting the color of an object image based on the transformation parameter has been proposed in JP2010-170316A. A method of extracting an amount of a feature regarding a color tone of an entire image indicating a real space and correcting a color of an object image based on the amount of a feature has been proposed in JP2013-025329A.
Incidentally, when a non-transparent object is irradiated with light, light and shade, and a shadow dependent on a relative position and posture between an object and a light source (in this specification, collectively referred to as a “shading effect”) occur. That is, an observer recognizes presence of this shading effect as “a normal appearance.”
However, according to the methods proposed in JP2010-170316A and JP2013-025329A, only color balance of an entire object image is considered, and the above-described shading effect is not considered at all. As a result, a user may feel uncomfortable with an appearance of the virtual object according to a state of an illumination within the real space.